I'm trying to eek the last bit of power out of the laptop battery, and turn down the temperature, too. Several optimization guides suggest lowering swappiness to below 20 by modifying /etc/sysctl.conf, but this file is missing in my VL5.8 Standard install. The setting can be changed manually by writing the desired number to the file /proc/sys/vm/swappiness, but this is erased on a reboot. How do I set this value automatically?